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kernel-ark/net/decnet/dn_nsp_out.c
Al Viro dd0fc66fb3 [PATCH] gfp flags annotations - part 1 
- added typedef unsigned int __nocast gfp_t;

 - replaced __nocast uses for gfp flags with gfp_t - it gives exactly
   the same warnings as far as sparse is concerned, doesn't change
   generated code (from gcc point of view we replaced unsigned int with
   typedef) and documents what's going on far better.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-08 15:00:57 -07:00

724 lines
18 KiB
C
Raw Blame History

/*
* DECnet An implementation of the DECnet protocol suite for the LINUX
* operating system. DECnet is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* DECnet Network Services Protocol (Output)
*
* Author: Eduardo Marcelo Serrat <emserrat@geocities.com>
*
* Changes:
*
* Steve Whitehouse: Split into dn_nsp_in.c and dn_nsp_out.c from
* original dn_nsp.c.
* Steve Whitehouse: Updated to work with my new routing architecture.
* Steve Whitehouse: Added changes from Eduardo Serrat's patches.
* Steve Whitehouse: Now conninits have the "return" bit set.
* Steve Whitehouse: Fixes to check alloc'd skbs are non NULL!
* Moved output state machine into one function
* Steve Whitehouse: New output state machine
* Paul Koning: Connect Confirm message fix.
* Eduardo Serrat: Fix to stop dn_nsp_do_disc() sending malformed packets.
* Steve Whitehouse: dn_nsp_output() and friends needed a spring clean
* Steve Whitehouse: Moved dn_nsp_send() in here from route.h
*/
/******************************************************************************
(c) 1995-1998 E.M. Serrat emserrat@geocities.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
*******************************************************************************/
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/inet.h>
#include <linux/route.h>
#include <net/sock.h>
#include <asm/system.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/termios.h>
#include <linux/interrupt.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/if_packet.h>
#include <net/neighbour.h>
#include <net/dst.h>
#include <net/flow.h>
#include <net/dn.h>
#include <net/dn_nsp.h>
#include <net/dn_dev.h>
#include <net/dn_route.h>
static int nsp_backoff[NSP_MAXRXTSHIFT + 1] = { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 };
static void dn_nsp_send(struct sk_buff *skb)
{
struct sock *sk = skb->sk;
struct dn_scp *scp = DN_SK(sk);
struct dst_entry *dst;
struct flowi fl;
skb->h.raw = skb->data;
scp->stamp = jiffies;
dst = sk_dst_check(sk, 0);
if (dst) {
try_again:
skb->dst = dst;
dst_output(skb);
return;
}
memset(&fl, 0, sizeof(fl));
fl.oif = sk->sk_bound_dev_if;
fl.fld_src = dn_saddr2dn(&scp->addr);
fl.fld_dst = dn_saddr2dn(&scp->peer);
dn_sk_ports_copy(&fl, scp);
fl.proto = DNPROTO_NSP;
if (dn_route_output_sock(&sk->sk_dst_cache, &fl, sk, 0) == 0) {
dst = sk_dst_get(sk);
sk->sk_route_caps = dst->dev->features;
goto try_again;
}
sk->sk_err = EHOSTUNREACH;
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_state_change(sk);
}
/*
* If sk == NULL, then we assume that we are supposed to be making
* a routing layer skb. If sk != NULL, then we are supposed to be
* creating an skb for the NSP layer.
*
* The eventual aim is for each socket to have a cached header size
* for its outgoing packets, and to set hdr from this when sk != NULL.
*/
struct sk_buff *dn_alloc_skb(struct sock *sk, int size, gfp_t pri)
{
struct sk_buff *skb;
int hdr = 64;
if ((skb = alloc_skb(size + hdr, pri)) == NULL)
return NULL;
skb->protocol = __constant_htons(ETH_P_DNA_RT);
skb->pkt_type = PACKET_OUTGOING;
if (sk)
skb_set_owner_w(skb, sk);
skb_reserve(skb, hdr);
return skb;
}
/*
* Calculate persist timer based upon the smoothed round
* trip time and the variance. Backoff according to the
* nsp_backoff[] array.
*/
unsigned long dn_nsp_persist(struct sock *sk)
{
struct dn_scp *scp = DN_SK(sk);
unsigned long t = ((scp->nsp_srtt >> 2) + scp->nsp_rttvar) >> 1;
t *= nsp_backoff[scp->nsp_rxtshift];
if (t < HZ) t = HZ;
if (t > (600*HZ)) t = (600*HZ);
if (scp->nsp_rxtshift < NSP_MAXRXTSHIFT)
scp->nsp_rxtshift++;
/* printk(KERN_DEBUG "rxtshift %lu, t=%lu\n", scp->nsp_rxtshift, t); */
return t;
}
/*
* This is called each time we get an estimate for the rtt
* on the link.
*/
static void dn_nsp_rtt(struct sock *sk, long rtt)
{
struct dn_scp *scp = DN_SK(sk);
long srtt = (long)scp->nsp_srtt;
long rttvar = (long)scp->nsp_rttvar;
long delta;
/*
* If the jiffies clock flips over in the middle of timestamp
* gathering this value might turn out negative, so we make sure
* that is it always positive here.
*/
if (rtt < 0)
rtt = -rtt;
/*
* Add new rtt to smoothed average
*/
delta = ((rtt << 3) - srtt);
srtt += (delta >> 3);
if (srtt >= 1)
scp->nsp_srtt = (unsigned long)srtt;
else
scp->nsp_srtt = 1;
/*
* Add new rtt varience to smoothed varience
*/
delta >>= 1;
rttvar += ((((delta>0)?(delta):(-delta)) - rttvar) >> 2);
if (rttvar >= 1)
scp->nsp_rttvar = (unsigned long)rttvar;
else
scp->nsp_rttvar = 1;
/* printk(KERN_DEBUG "srtt=%lu rttvar=%lu\n", scp->nsp_srtt, scp->nsp_rttvar); */
}
/**
* dn_nsp_clone_and_send - Send a data packet by cloning it
* @skb: The packet to clone and transmit
* @gfp: memory allocation flag
*
* Clone a queued data or other data packet and transmit it.
*
* Returns: The number of times the packet has been sent previously
*/
static inline unsigned dn_nsp_clone_and_send(struct sk_buff *skb,
gfp_t gfp)
{
struct dn_skb_cb *cb = DN_SKB_CB(skb);
struct sk_buff *skb2;
int ret = 0;
if ((skb2 = skb_clone(skb, gfp)) != NULL) {
ret = cb->xmit_count;
cb->xmit_count++;
cb->stamp = jiffies;
skb2->sk = skb->sk;
dn_nsp_send(skb2);
}
return ret;
}
/**
* dn_nsp_output - Try and send something from socket queues
* @sk: The socket whose queues are to be investigated
* @gfp: The memory allocation flags
*
* Try and send the packet on the end of the data and other data queues.
* Other data gets priority over data, and if we retransmit a packet we
* reduce the window by dividing it in two.
*
*/
void dn_nsp_output(struct sock *sk)
{
struct dn_scp *scp = DN_SK(sk);
struct sk_buff *skb;
unsigned reduce_win = 0;
/*
* First we check for otherdata/linkservice messages
*/
if ((skb = skb_peek(&scp->other_xmit_queue)) != NULL)
reduce_win = dn_nsp_clone_and_send(skb, GFP_ATOMIC);
/*
* If we may not send any data, we don't.
* If we are still trying to get some other data down the
* channel, we don't try and send any data.
*/
if (reduce_win || (scp->flowrem_sw != DN_SEND))
goto recalc_window;
if ((skb = skb_peek(&scp->data_xmit_queue)) != NULL)
reduce_win = dn_nsp_clone_and_send(skb, GFP_ATOMIC);
/*
* If we've sent any frame more than once, we cut the
* send window size in half. There is always a minimum
* window size of one available.
*/
recalc_window:
if (reduce_win) {
scp->snd_window >>= 1;
if (scp->snd_window < NSP_MIN_WINDOW)
scp->snd_window = NSP_MIN_WINDOW;
}
}
int dn_nsp_xmit_timeout(struct sock *sk)
{
struct dn_scp *scp = DN_SK(sk);
dn_nsp_output(sk);
if (!skb_queue_empty(&scp->data_xmit_queue) ||
!skb_queue_empty(&scp->other_xmit_queue))
scp->persist = dn_nsp_persist(sk);
return 0;
}
static inline unsigned char *dn_mk_common_header(struct dn_scp *scp, struct sk_buff *skb, unsigned char msgflag, int len)
{
unsigned char *ptr = skb_push(skb, len);
BUG_ON(len < 5);
*ptr++ = msgflag;
*((unsigned short *)ptr) = scp->addrrem;
ptr += 2;
*((unsigned short *)ptr) = scp->addrloc;
ptr += 2;
return ptr;
}
static unsigned short *dn_mk_ack_header(struct sock *sk, struct sk_buff *skb, unsigned char msgflag, int hlen, int other)
{
struct dn_scp *scp = DN_SK(sk);
unsigned short acknum = scp->numdat_rcv & 0x0FFF;
unsigned short ackcrs = scp->numoth_rcv & 0x0FFF;
unsigned short *ptr;
BUG_ON(hlen < 9);
scp->ackxmt_dat = acknum;
scp->ackxmt_oth = ackcrs;
acknum |= 0x8000;
ackcrs |= 0x8000;
/* If this is an "other data/ack" message, swap acknum and ackcrs */
if (other) {
unsigned short tmp = acknum;
acknum = ackcrs;
ackcrs = tmp;
}
/* Set "cross subchannel" bit in ackcrs */
ackcrs |= 0x2000;
ptr = (unsigned short *)dn_mk_common_header(scp, skb, msgflag, hlen);
*ptr++ = dn_htons(acknum);
*ptr++ = dn_htons(ackcrs);
return ptr;
}
static unsigned short *dn_nsp_mk_data_header(struct sock *sk, struct sk_buff *skb, int oth)
{
struct dn_scp *scp = DN_SK(sk);
struct dn_skb_cb *cb = DN_SKB_CB(skb);
unsigned short *ptr = dn_mk_ack_header(sk, skb, cb->nsp_flags, 11, oth);
if (unlikely(oth)) {
cb->segnum = scp->numoth;
seq_add(&scp->numoth, 1);
} else {
cb->segnum = scp->numdat;
seq_add(&scp->numdat, 1);
}
*(ptr++) = dn_htons(cb->segnum);
return ptr;
}
void dn_nsp_queue_xmit(struct sock *sk, struct sk_buff *skb,
gfp_t gfp, int oth)
{
struct dn_scp *scp = DN_SK(sk);
struct dn_skb_cb *cb = DN_SKB_CB(skb);
unsigned long t = ((scp->nsp_srtt >> 2) + scp->nsp_rttvar) >> 1;
cb->xmit_count = 0;
dn_nsp_mk_data_header(sk, skb, oth);
/*
* Slow start: If we have been idle for more than
* one RTT, then reset window to min size.
*/
if ((jiffies - scp->stamp) > t)
scp->snd_window = NSP_MIN_WINDOW;
if (oth)
skb_queue_tail(&scp->other_xmit_queue, skb);
else
skb_queue_tail(&scp->data_xmit_queue, skb);
if (scp->flowrem_sw != DN_SEND)
return;
dn_nsp_clone_and_send(skb, gfp);
}
int dn_nsp_check_xmit_queue(struct sock *sk, struct sk_buff *skb, struct sk_buff_head *q, unsigned short acknum)
{
struct dn_skb_cb *cb = DN_SKB_CB(skb);
struct dn_scp *scp = DN_SK(sk);
struct sk_buff *skb2, *list, *ack = NULL;
int wakeup = 0;
int try_retrans = 0;
unsigned long reftime = cb->stamp;
unsigned long pkttime;
unsigned short xmit_count;
unsigned short segnum;
skb2 = q->next;
list = (struct sk_buff *)q;
while(list != skb2) {
struct dn_skb_cb *cb2 = DN_SKB_CB(skb2);
if (dn_before_or_equal(cb2->segnum, acknum))
ack = skb2;
/* printk(KERN_DEBUG "ack: %s %04x %04x\n", ack ? "ACK" : "SKIP", (int)cb2->segnum, (int)acknum); */
skb2 = skb2->next;
if (ack == NULL)
continue;
/* printk(KERN_DEBUG "check_xmit_queue: %04x, %d\n", acknum, cb2->xmit_count); */
/* Does _last_ packet acked have xmit_count > 1 */
try_retrans = 0;
/* Remember to wake up the sending process */
wakeup = 1;
/* Keep various statistics */
pkttime = cb2->stamp;
xmit_count = cb2->xmit_count;
segnum = cb2->segnum;
/* Remove and drop ack'ed packet */
skb_unlink(ack, q);
kfree_skb(ack);
ack = NULL;
/*
* We don't expect to see acknowledgements for packets we
* haven't sent yet.
*/
WARN_ON(xmit_count == 0);
/*
* If the packet has only been sent once, we can use it
* to calculate the RTT and also open the window a little
* further.
*/
if (xmit_count == 1) {
if (dn_equal(segnum, acknum))
dn_nsp_rtt(sk, (long)(pkttime - reftime));
if (scp->snd_window < scp->max_window)
scp->snd_window++;
}
/*
* Packet has been sent more than once. If this is the last
* packet to be acknowledged then we want to send the next
* packet in the send queue again (assumes the remote host does
* go-back-N error control).
*/
if (xmit_count > 1)
try_retrans = 1;
}
if (try_retrans)
dn_nsp_output(sk);
return wakeup;
}
void dn_nsp_send_data_ack(struct sock *sk)
{
struct sk_buff *skb = NULL;
if ((skb = dn_alloc_skb(sk, 9, GFP_ATOMIC)) == NULL)
return;
skb_reserve(skb, 9);
dn_mk_ack_header(sk, skb, 0x04, 9, 0);
dn_nsp_send(skb);
}
void dn_nsp_send_oth_ack(struct sock *sk)
{
struct sk_buff *skb = NULL;
if ((skb = dn_alloc_skb(sk, 9, GFP_ATOMIC)) == NULL)
return;
skb_reserve(skb, 9);
dn_mk_ack_header(sk, skb, 0x14, 9, 1);
dn_nsp_send(skb);
}
void dn_send_conn_ack (struct sock *sk)
{
struct dn_scp *scp = DN_SK(sk);
struct sk_buff *skb = NULL;
struct nsp_conn_ack_msg *msg;
if ((skb = dn_alloc_skb(sk, 3, sk->sk_allocation)) == NULL)
return;
msg = (struct nsp_conn_ack_msg *)skb_put(skb, 3);
msg->msgflg = 0x24;
msg->dstaddr = scp->addrrem;
dn_nsp_send(skb);
}
void dn_nsp_delayed_ack(struct sock *sk)
{
struct dn_scp *scp = DN_SK(sk);
if (scp->ackxmt_oth != scp->numoth_rcv)
dn_nsp_send_oth_ack(sk);
if (scp->ackxmt_dat != scp->numdat_rcv)
dn_nsp_send_data_ack(sk);
}
static int dn_nsp_retrans_conn_conf(struct sock *sk)
{
struct dn_scp *scp = DN_SK(sk);
if (scp->state == DN_CC)
dn_send_conn_conf(sk, GFP_ATOMIC);
return 0;
}
void dn_send_conn_conf(struct sock *sk, gfp_t gfp)
{
struct dn_scp *scp = DN_SK(sk);
struct sk_buff *skb = NULL;
struct nsp_conn_init_msg *msg;
unsigned char len = scp->conndata_out.opt_optl;
if ((skb = dn_alloc_skb(sk, 50 + scp->conndata_out.opt_optl, gfp)) == NULL)
return;
msg = (struct nsp_conn_init_msg *)skb_put(skb, sizeof(*msg));
msg->msgflg = 0x28;
msg->dstaddr = scp->addrrem;
msg->srcaddr = scp->addrloc;
msg->services = scp->services_loc;
msg->info = scp->info_loc;
msg->segsize = dn_htons(scp->segsize_loc);
*skb_put(skb,1) = len;
if (len > 0)
memcpy(skb_put(skb, len), scp->conndata_out.opt_data, len);
dn_nsp_send(skb);
scp->persist = dn_nsp_persist(sk);
scp->persist_fxn = dn_nsp_retrans_conn_conf;
}
static __inline__ void dn_nsp_do_disc(struct sock *sk, unsigned char msgflg,
unsigned short reason, gfp_t gfp,
struct dst_entry *dst,
int ddl, unsigned char *dd, __u16 rem, __u16 loc)
{
struct sk_buff *skb = NULL;
int size = 7 + ddl + ((msgflg == NSP_DISCINIT) ? 1 : 0);
unsigned char *msg;
if ((dst == NULL) || (rem == 0)) {
if (net_ratelimit())
printk(KERN_DEBUG "DECnet: dn_nsp_do_disc: BUG! Please report this to SteveW@ACM.org rem=%u dst=%p\n", (unsigned)rem, dst);
return;
}
if ((skb = dn_alloc_skb(sk, size, gfp)) == NULL)
return;
msg = skb_put(skb, size);
*msg++ = msgflg;
*(__u16 *)msg = rem;
msg += 2;
*(__u16 *)msg = loc;
msg += 2;
*(__u16 *)msg = dn_htons(reason);
msg += 2;
if (msgflg == NSP_DISCINIT)
*msg++ = ddl;
if (ddl) {
memcpy(msg, dd, ddl);
}
/*
* This doesn't go via the dn_nsp_send() function since we need
* to be able to send disc packets out which have no socket
* associations.
*/
skb->dst = dst_clone(dst);
dst_output(skb);
}
void dn_nsp_send_disc(struct sock *sk, unsigned char msgflg,
unsigned short reason, gfp_t gfp)
{
struct dn_scp *scp = DN_SK(sk);
int ddl = 0;
if (msgflg == NSP_DISCINIT)
ddl = scp->discdata_out.opt_optl;
if (reason == 0)
reason = scp->discdata_out.opt_status;
dn_nsp_do_disc(sk, msgflg, reason, gfp, sk->sk_dst_cache, ddl,
scp->discdata_out.opt_data, scp->addrrem, scp->addrloc);
}
void dn_nsp_return_disc(struct sk_buff *skb, unsigned char msgflg,
unsigned short reason)
{
struct dn_skb_cb *cb = DN_SKB_CB(skb);
int ddl = 0;
gfp_t gfp = GFP_ATOMIC;
dn_nsp_do_disc(NULL, msgflg, reason, gfp, skb->dst, ddl,
NULL, cb->src_port, cb->dst_port);
}
void dn_nsp_send_link(struct sock *sk, unsigned char lsflags, char fcval)
{
struct dn_scp *scp = DN_SK(sk);
struct sk_buff *skb;
unsigned char *ptr;
gfp_t gfp = GFP_ATOMIC;
if ((skb = dn_alloc_skb(sk, DN_MAX_NSP_DATA_HEADER + 2, gfp)) == NULL)
return;
skb_reserve(skb, DN_MAX_NSP_DATA_HEADER);
ptr = skb_put(skb, 2);
DN_SKB_CB(skb)->nsp_flags = 0x10;
*ptr++ = lsflags;
*ptr = fcval;
dn_nsp_queue_xmit(sk, skb, gfp, 1);
scp->persist = dn_nsp_persist(sk);
scp->persist_fxn = dn_nsp_xmit_timeout;
}
static int dn_nsp_retrans_conninit(struct sock *sk)
{
struct dn_scp *scp = DN_SK(sk);
if (scp->state == DN_CI)
dn_nsp_send_conninit(sk, NSP_RCI);
return 0;
}
void dn_nsp_send_conninit(struct sock *sk, unsigned char msgflg)
{
struct dn_scp *scp = DN_SK(sk);
struct nsp_conn_init_msg *msg;
unsigned char aux;
unsigned char menuver;
struct dn_skb_cb *cb;
unsigned char type = 1;
gfp_t allocation = (msgflg == NSP_CI) ? sk->sk_allocation : GFP_ATOMIC;
struct sk_buff *skb = dn_alloc_skb(sk, 200, allocation);
if (!skb)
return;
cb = DN_SKB_CB(skb);
msg = (struct nsp_conn_init_msg *)skb_put(skb,sizeof(*msg));
msg->msgflg = msgflg;
msg->dstaddr = 0x0000; /* Remote Node will assign it*/
msg->srcaddr = scp->addrloc;
msg->services = scp->services_loc; /* Requested flow control */
msg->info = scp->info_loc; /* Version Number */
msg->segsize = dn_htons(scp->segsize_loc); /* Max segment size */
if (scp->peer.sdn_objnum)
type = 0;
skb_put(skb, dn_sockaddr2username(&scp->peer, skb->tail, type));
skb_put(skb, dn_sockaddr2username(&scp->addr, skb->tail, 2));
menuver = DN_MENUVER_ACC | DN_MENUVER_USR;
if (scp->peer.sdn_flags & SDF_PROXY)
menuver |= DN_MENUVER_PRX;
if (scp->peer.sdn_flags & SDF_UICPROXY)
menuver |= DN_MENUVER_UIC;
*skb_put(skb, 1) = menuver; /* Menu Version */
aux = scp->accessdata.acc_userl;
*skb_put(skb, 1) = aux;
if (aux > 0)
memcpy(skb_put(skb, aux), scp->accessdata.acc_user, aux);
aux = scp->accessdata.acc_passl;
*skb_put(skb, 1) = aux;
if (aux > 0)
memcpy(skb_put(skb, aux), scp->accessdata.acc_pass, aux);
aux = scp->accessdata.acc_accl;
*skb_put(skb, 1) = aux;
if (aux > 0)
memcpy(skb_put(skb, aux), scp->accessdata.acc_acc, aux);
aux = scp->conndata_out.opt_optl;
*skb_put(skb, 1) = aux;
if (aux > 0)
memcpy(skb_put(skb,aux), scp->conndata_out.opt_data, aux);
scp->persist = dn_nsp_persist(sk);
scp->persist_fxn = dn_nsp_retrans_conninit;
cb->rt_flags = DN_RT_F_RQR;
dn_nsp_send(skb);
}
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